Running DeepSeek V4.1 Flash on a Single DGX Spark (128 GB): 113.6 GB Base Model + 40 MB Domain Sidecars

Sharing our engineering work on a single NVIDIA DGX Spark (GB10, 128 GB unified memory). We use ds4, a native C/CUDA inference engine, to run DeepSeek V4.1 Flash from an official checkpoint of roughly 510 GB on one device.

The core approach uses vector quantization to split the model into three files:

  • ① 113.6 GB general base model (~1.6 bits/weight)

  • ② ~40 MB domain sidecar files, switchable on demand for finance, code, law, medical, and science domains

  • ③ Post-training file, re-solved nightly

The original FP8 203 GB n-gram memory table stays on SSD, and each token reads only about 6 KB from it.

Measured on a single DGX Spark:

Metric Result
Prefill (12.5k-token prompt) 489 tokens/s
Decode (normal greedy, short context) 30.7 tokens/s
Decode (speculative sampling, 14k context) 43.0 tokens/s
Context length 1M tokens
KV cache 0.89 GB

Distribution agreement with the original model (Restore rate Σmin):

Domain Restore rate
Finance 0.745
Code 0.803
Law 0.760
Medical 0.739
Science 0.753

Same top-1 ratio ranges from 72.8% to 82.3%.

All CUDA kernels, quantization formats, and solvers are our own work. The model architecture belongs to DeepSeek. MIT license.

Original README: README.md · wenzhouwu/YoungAi-DeepSeek-V4.1-Flash at main